scholarly journals The Program Cell Death (Apoptosis) and the Therapy of Cancer

2021 ◽  
Author(s):  
Hilal Kalkan

Apoptosis plays many vital roles in maintaining organ homeostasis and represents type I programmed cell death. Programmed cell death happens when the DNA damage is irremediable and has two important pathways, the intrinsic death pathway also known as the mitochondrial pathway, and the extrinsic programmed cell death pathway. Any defects in the regulation of these crucial pathways have been associated with many disorders, most importantly cancer. Therefore, understanding the molecular basis of apoptosis is essential for the treatment of incurable cancer. To date, several anti-cancer drugs have been developed by targeting anti-apoptotic proteins, which are upregulated in many cancers. Nonetheless, a disease progression often time warranted due to the deregulation of several anti or pro-apoptotic proteins which also contribute to drug resistance. Hence, it is important to understand the maintenance and counteraction of apoptosis and improve successful new pharmacological applications of cell death mechanisms for future therapies. This chapter discusses the mechanism of apoptosis and emerging principles of drug resistance in cancer.

Author(s):  
Luciano Carotenuto ◽  
Vincenza Pace ◽  
Dina Bellizzi ◽  
Giovanna De Benedictis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Francesco Monticolo ◽  
Emanuela Palomba ◽  
Maria Luisa Chiusano

AbstractProgrammed cell death involves complex molecular pathways in both eukaryotes and prokaryotes. In Escherichia coli, the toxin–antitoxin system (TA-system) has been described as a programmed cell death pathway in which mRNA and ribosome organizations are modified, favoring the production of specific death-related proteins, but also of a minor portion of survival proteins, determining the destiny of the cell population. In the eukaryote Saccharomyces cerevisiae, the ribosome was shown to change its stoichiometry in terms of ribosomal protein content during stress response, affecting the relative proportion between ohnologs, i.e., the couple of paralogs derived by a whole genome duplication event. Here, we confirm the differential expression of ribosomal proteins in yeast also during programmed cell death induced by acetic acid, and we highlight that also in this case pairs of ohnologs are involved. We also show that there are different trends in cytosolic and mitochondrial ribosomal proteins gene expression during the process. Moreover, we show that the exposure to acetic acid induces the differential expression of further genes coding for products related to translation processes and to rRNA post-transcriptional maturation, involving mRNA decapping, affecting translation accuracy, and snoRNA synthesis. Our results suggest that the reprogramming of the overall translation apparatus, including the cytosolic ribosome reorganization, are relevant events in yeast programmed cell death induced by acetic acid.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jennifer M. Peña ◽  
Samantha M. Prezioso ◽  
Kirsty A. McFarland ◽  
Tracy K. Kambara ◽  
Kathryn M. Ramsey ◽  
...  

AbstractIn Pseudomonas aeruginosa the alp system encodes a programmed cell death pathway that is switched on in a subset of cells in response to DNA damage and is linked to the virulence of the organism. Here we show that the central regulator of this pathway, AlpA, exerts its effects by acting as an antiterminator rather than a transcription activator. In particular, we present evidence that AlpA positively regulates the alpBCDE cell lysis genes, as well as genes in a second newly identified target locus, by recognizing specific DNA sites within the promoter, then binding RNA polymerase directly and allowing it to bypass intrinsic terminators positioned downstream. AlpA thus functions in a mechanistically unusual manner to control the expression of virulence genes in this opportunistic pathogen.


2009 ◽  
Vol 11 (1) ◽  
pp. 138-155 ◽  
Author(s):  
Oliver Goldmann ◽  
Inka Sastalla ◽  
Melissa Wos-Oxley ◽  
Manfred Rohde ◽  
Eva Medina

2018 ◽  
Vol 101 ◽  
pp. 129-136 ◽  
Author(s):  
Cagri Urfali-Mamatoglu ◽  
Hasan Hüseyin Kazan ◽  
Ufuk Gündüz

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3247
Author(s):  
Lingxiao Ye ◽  
Zhengxin Zhu ◽  
Xiaochuan Chen ◽  
Haoran Zhang ◽  
Jiaqi Huang ◽  
...  

Binding of programmed cell death ligand 1 (PD-L1) to its receptor programmed cell death protein 1 (PD-1) can lead to the inactivation of cytotoxic T lymphocytes, which is one of the mechanisms for immune escape of tumors. Immunotherapy based on this mechanism has been applied in clinic with some remaining issues such as drug resistance. Exosomal PD-L1 derived from tumor cells is considered to play a key role in mediating drug resistance. Here, the effects of various tumor-derived exosomes and tumor-derived exosomal PD-L1 on tumor progression are summarized and discussed. Researchers have found that high expression of exosomal PD-L1 can inhibit T cell activation in in vitro experiments, but the function of exosomal PD-L1 in vivo remains controversial. In addition, the circulating exosomal PD-L1 has high potential to act as an indicator to evaluate the clinical effect. Moreover, therapeutic strategy targeting exosomal PD-L1 is discussed, such as inhibiting the biogenesis or secretion of exosomes. Besides, some specific methods based on the strategy of inhibiting exosomes are concluded. Further study of exosomal PD-L1 may provide an effective and safe approach for tumor treatment, and targeting exosomal PD-L1 by inhibiting exosomes may be a potential method for tumor treatment.


2019 ◽  
Vol 21 (1) ◽  
pp. 137-140
Author(s):  
O. V. Dolgikh ◽  
N. V. Zaitseva ◽  
D. G. Dianova ◽  
A. V. Krivtsov ◽  
K. D. Starkova ◽  
...  

Apoptosis is defined as a highly regulated form of programmed cell death with typical morphological and biochemical features. A variety of factors, including heavy metals, may influence the intensity of programmed cell death. The aim of the work was to simulate apoptosis in an in vitrosystem under the conditions of stable strontium exposure. The children’s population consuming drinking water with high strontium (Sr2+) content (n = 49) was observed. The level of lymphocyte apoptosis was determined with flow cytometry technique, by means of labeled annexin V-FITC conjugate (AnnV-FITC) and propidium iodide (PI) staining. AnnV-FITC+PI- cells were regarded as early apoptotic forms, whereas late apoptotic and/or necrotic cells were AnnV-FITC+PI+. The isolated leukocytes were incubated with Sr2+ at a concentration of 7.0 mg/l, the maximal permitted concentration (MPC) for water of aqueous objects, for 4 hours at 37 ºC. Expression of CD95 and p53 apoptosis markers was performed by flow cytometry using labeled monoclonal antibodies.In vitroexposure to strontium was associated with significantly decreased expression of apoptosisregulating factors, i.e., membrane marker CD95 and intracellular transcription protein p53, 1.56- and 1.68-fold, respectively. Meanwhile, we revealed a significantly (4.68-fold) decreased amounts of AnnV-FITC+PI--cells, as well as a statistically significant (1.35-fold) increase of the AnnV-FITC+PI+-cells. Moreover, the amounts of AnnV-FITC+ PI--lymphocytes in all samples were below the physiological ranges and control values. The number of samples with higher contents of AnnV-FITC+PI+-lymphocyte exceeding the established standards and control values, was 30.8%. Thus, it has been experimentally proven that strontium, at a concentration corresponding to MPC for water objects may significantly inhibit cell death along apoptotic pathways, with switching to necrotic cell death mechanisms, according to phosphatidylserine contents, as detected by annexin V binding test. The data have revealed an ability of strontium to have a significant effect upon the parameters of regulation and maintenance of cellular homeostasis, by influencing the apoptosis intensity, due to shifting a balance towards necrosis and reducing expression of apoptosis-regulating factors. The results of this study may be used in order to identify some marker indexes of immune disorders potentially induced by external influence of strontium upon human health under specific environmental factors.


1998 ◽  
Vol 16 (11) ◽  
pp. 3674-3690 ◽  
Author(s):  
D M Bradshaw ◽  
R J Arceci

For cytotoxic agents to have an effect on tumor cells, drugs must first be transported into the cell, potentially be metabolized to an active form, and interact appropriately with target molecules. A final common pathway of cytotoxic agents is usually the initiation of programmed cell death, or apoptosis. Tumor cells overcome the effects of cytotoxic agents at one or more of these levels. The classic multidrug-resistance (MDR) phenotype, as mediated by the drug efflux pump, P-glycoprotein, is one of the most extensively studied mechanisms of drug resistance. Additional drug transporters, such as the multidrug resistance-associated proteins (MRPs), have also been identified and can convey drug-resistance phenotypes. Important questions remain as to how and whether such transport systems can be specifically measured and effectively targeted to improve therapeutic outcomes. Furthermore, alterations in drug targets, drug metabolism, repair of DNA damage caused by drugs, and the inability to initiate programmed cell death can all contribute to drug resistance and must be ultimately considered in the explanation of tumor-cell resistance to therapy. Continued exploration of the pharmacologic methods to circumvent drug resistance, as well as strategies that involve targeted therapy and immunomodulation, should increase the specificity and efficacy of treatments for patients with cancer.


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